Alarm as human embryo is cloned

Scientists have for the first time created a cloned human embryo in a breakthrough that has sparked alarm across the world.

The six tiny cell embryos represent a major genetic-research development that crosses one of the most fundamental ethical boundaries in science.

In experiments carried out by American firm Advanced Cell Technology, a woman's egg cell was coaxed into becoming an early embryo without any form of fertilisation.

Using techniques pioneered by British experts who created Dolly the Sheep, researchers removed DNA - the blueprint for life - from the eggs and replaced it with DNA from adult cells. It was then stimulated with electricity, and the embryos began to develop in three out of eight cases.

Human embryo clones have become a scientific "holy grail" because the embryos contain stem cells, which can be used to create virtually any human tissue.

They are potentially vital for transplant operations and therapies for conditions including strokes, cancer, Aids, Parkinson's and Alzheimer's disease.

The firm, based in Worcester, Massachusetts, said there were no plans to clone a human being. Dr Michael West said: "We could implant these cells into a woman's uterus and make a cloned human being, but that's not what we are doing. We are doing it to help cure diseases."

But Dr Patrick Dixon, a UK authority on the ethics of cloning, claimed: "It is now only a matter of time before a clone human is born."

Emergency legislation to ban human cloning in Britain is today being rushed through the Lords.

What is therapeutic cloning?
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